Washington -- The top Democrat and Republican on the Senate Environment and Public Works Committee teamed up Thursday to pressure the Obama administration to commit more funding from the Harbor Maintenance Trust Fund for maintaining shipping channels. Only half the fund, financed by cargo fees by U.S. shippers, has been used for its intended purpose -- navigation channel maintenance --since its creation in 1986, according to the committee.

"Continued maintenance of port facilities is critical for the commerce and jobs that rely on these economic hubs, and that is why we must increase investment from the Harbor Maintenance Trust Fund," said Committee Chairwoman Barbara Boxer, D-Calif."

Sen. David Vitter, R-La., the panel's new ranking Republican, agreed, saying that $7 billion from the fund has been diverted from the fund over the last 26 years. "That money is gone," Vitter said.

As a result, he said, deep-draft channels in the Lower Mississippi River aren't being maintained to authorized depths and widths - in effect forcing key routes to be turned one way. He said it would be like turning I-10 one way form noon to midnight and the other way from midnight to noon.

Jo-Ellen Darcy, assistant secretary of the Army for Civil Works, said the Obama administration committed a record $848 million for river maintenance in the current budget. That's large investment, she said, given the nation's other needs and deficit problems. But that's still only about half as much as the Trust Fund produces, Boxer said.

Still, the Obama administration isn't the first not to allocate the entire trust fund for harbor maintenance.

Michael Lorino Jr., speaking for the Associated Branch Pilots in New Orleans, said the Army Corps of Engineers is currently underfunding work on the Lower Mississippi River by $50 million a year.

"A channel at less than authorized dimensions is like a highway with only one lane open, causing painful and costly delays while also increasing the possibility of an accident," Lorino told the committee. "Further, these inefficiencies increase transportation costs significantly, making it even more difficult to compete globally with other nations who may already have an edge in manufacturing costs."

He said Obama administrations plans to expand the U.S. economy by increasing exports can't happen unless shipping channels are better maintained.

Boxer and Vitter are working on a new water resources bill with language Boxer says will reform the Harbor Maintenance Trust Fund. Last year, Rep. Charles Boustany, R-Lafayette, got the House to approve a bill to spend more on dredging, but that measure didn't make it through the Senate.

This was the first committee meeting in which Vitter served as ranking Republican. And at least for day one, Boxer and Vitter seemed to get along just fine, though, over the years they've spurred on other issues that typically divide liberals and conservatives.

"I would like to welcome the Committee's new ranking member, Senator Vitter," Boxer said at the beginning of the hearing. "For many years, Senator Vitter has been a leader in calling for investment in our nation's ports. I am excited about the opportunity to work together with Senator Vitter and the other members of this Committee on this and many other important water infrastructure issues."